Integrated 75-100 GHz In-Band Full-Duplex Front End GaN MMIC

This paper presents a fully integrated 75-100 GHz in-band full-duplex (IBFD) front end MMIC. The MMIC is implemented in a 40-nm HEMT GaN-on-SiC process and consists of a tunable analog self-interference cancellation (SIC) network, power amplifier (PA), and low noise amplifier (LNA). The tunable SIC network, made of three Lange couplers, is connected directly to the antenna port. With tunable loads at the isolated port for two of the couplers, this analog network demonstrates a SIC of 30 dB from transmit to receive based on tunable load biasing. The analog SIC network is then integrated on chip with a three-stage PA and a three-stage LNA, demonstrating a system transmit gain of 13.6 dB and a receive gain of 17 dB.